


Best Friend's Brother

by allofthepixels



Category: Supernatural
Genre: College AU, HS AU, M/M, Ticklish Castiel, Ticklish Dean, Ticklish Sam
Language: English
Status: Completed
Published: 2015-02-05
Updated: 2015-02-05
Packaged: 2018-03-10 14:58:37
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,912
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3294677
Author URL: https://archiveofourown.org/users/allofthepixels/pseuds/allofthepixels
Summary: <blockquote class="userstuff">
              <p>Castiel is Sam’s best friend. Dean, Sam’s sexy older brother, is home for the summer from college and is just about all Cas can think about. Dean likes to tease his brother and his cute shy friend and fluffy stuff ensues</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> Cas has a secret crush on his best friend’s hot older brother. It’s not much of a secret, though.

When he knocked that afternoon (really more out of courtesy than necessity) around 2 P.M, the last thing he was expecting was a great big eye-full of sex god. When the door heaved open and an imposing shirtless figure squinted at him, freshly out of sleep, Cas wanted to shrink into the floor. 

He’d put two and two together quickly, realizing that this man was his friend’s older brother, Dean. He’d never met the older Winchester who played lacrosse for some college in the east. He’d only seen a few of the admittedly sparse family photos in the house (as most had been lost in the house fire that took the boys’ mother eight years ago) but he couldn’t in his wildest dreams have imagined that Dean looked like this. High Definition handsome.

A constellation of freckles flowed over the bridge of his nose, a few visibly dotting his shoulders. He was built: athletic and sturdy. His jaw had a hint of stubble and under hooded lids Cas could see this glimmer of green that left him just a bit breathless. His mouth was dry and the look on Dean’s face, sleepy and surprised, left him at loss for words. 

”Erm, hello,” he stuttered, wincing at the sound of his own voice. “Is this a bad time?”

Dean’s eyes kind of widened a bit, finally waking up before he cleared his throat. 

"No, it’s fine! I—" he rubbed his eyes, straightening out his back. "Uh, you here for Sammy?" 

"Yeah, he told me to come by after noon and—"

"Cas?" Sam appeared by the door. "Come on in!"

As his younger brother started to chatter about whatever nerd work they had on their agenda, Dean took in his friend. He had this intense face and infuriatingly blue eyes and this messy sex hair going on. He found himself fighting to look less awestruck, trying to keep Sam from noticing. But from the shit-eating grin on his little brother’s face hidden beneath his shaggy mane of hair, Dean had a funny feeling he was caught. 

And if he spent that morning taking several extra detours through the kitchen to catch a glimpse of mussed up dark hair or pretty blue eyes, that was no one’s business but his own. 

—————

In the days that followed, Dean saw more and more of his brother’s handsome friend. Granted, it wasn’t at all accidental.

"Knock it off, Sam," Dean heard the scuffle from his room. He’d paced back forth in front of the door for almost a solid minute trying to decide whether he should step outside. 

He’d already left his room to go for a run (read: do a lap around the block and come home shirtless, to watch the blush rise in the dark-haired boy), to make a protein shake (to linger in the kitchen in only a pair of basketball shorts post-shower) and to find his favorite Clint Eastwood DVD box set (to bend over the entertainment center for extended periods of time while his brother and his friend watched a marathon-worth of movies on Netflix.)

It wasn’t the first night Cas stayed over since Dean returned home for the summer, but Dean was going insane from constantly sharing space with him. He’d already received more than his fair share of flack from Sam for his “shameless eyeballing” and he didn’t want to get called out for hovering, no matter how desperately he wanted to hover.

A loud thud sounded and a groan that had to have been Sam’s followed, Dean smirked. He couldn’t lie, the glimpse he’s had of Sam and Cas’ friendship had really sped up the process of endearing the kid to him; he made his brother smile and made him feel less alone. The house was decidedly happier. 

Another thud and a yelp came from the living room and Dean couldn’t resist going to check it out. What he found had him hiding his face in his hands to disguise his laughter.

"Dean! Help!"

Sam was belly down, hands pinned behind his back and held down by Cas’ butt, socked feet kicking haphazardly over the arm of the couch. 

"Problem Sammy?" Dean laughed as his brother’s face grew pink. "What’d he do, Cas?"

"J-just being a nuisance," the other boy muttered, looking away. Dean thought he saw a hint of red at the back of his neck, but decided not to mention it. 

"Not surprised," Dean crouched and spidered his fingers over Sam’s nearest foot, smiling as his brother yelped and seized up against Cas with extra force. 

"Wait…" A devious, if unfairly sexy, look of realization came onto Cas’ face. "Sam’s ticklish?"

"Stupid ticklish," Dean grinned back, straddling his brother’s ankles like a bronco. Sam’s body went stiff. 

"Don’t talk about me like I’m not here and get the f— PLEASE DON’T!" Sam was cut off by Cas digging his long fingers under his rib cage. 

"You-hoo-hoo two-hoo tag teaming is too cute,” Sam huffed between giggles. 

"Hm?" Dean paused a bit, his fingers lightly scraping rather than frantically scratching, feeling as though part of this conversation was going over his head. "What’s that?"

"Yeah, but why don’t you tell Dean why I was a nuisance, Cas?” Sam gasped between giggles as Cas continued his assault on his sides.

"Fuck off, Sam," the older boy jammed his fingers under his friend’s arms in retribution. His eyes nearly bugged out of his head and a squeal flew out of his mouth. 

"Do-ho-hon’t you want to know, Dean?" 

Cas seemed to increase his attack on Sam with every additional word and Dean’s interest was peaked. They knew something he didn’t know.

"What’s he talking ‘bout?"

"Yeah, Cahahas, why dont you tehehell him?" Sam teased. "Why can’t Dean know?"

"Yeah, why can’t I know?" Dean watched color rise into the dark-haired boy’s cheeks and it was almost too endearing for words. "Come onnnn."

He punctuated his request with a scrape of fingers to Cas’ side. 

"Do-hon’t!" the kid jumped what had to be a half foot in the air landing in a heap on the floor with the added help of Sam’s bucking legs. The two Winchesters’ eyes met and they wore identical smiles.

"Double team?" 

"Double team."

Sam landed on Cas’ legs, just below the knee with what could only be described as a bounce. Cas reached up to push him off but it gave Dean easy access to both of his arms and in seconds the brothers had him pinned to the plush carpet, cursing between intense bouts of struggling.

"So what’s the story?" Dean asked, moving Cas’ up and under his knees and freeing up both hands, clasping them eagerly over his head. Cas held his breath and Dean tried not to let his face show how freaking cute he found this whole situation. "Wanna just tell me? Make it less painful?" 

Cas’ face paled and he shot Sam a panicked look, but his friend seemed oblivious. Just before he’d been teasing Cas about being “mooney-eyed” for his brother. He wasn’t entirely wrong (Dean’s hunt for a DVD was essentially ten minutes of Cas staring directly at his ass and fighting his need to salivate.) Sam seems to be out to ensure Cas never showed his face around the Winchester house again. 

"Aw, Sammy, remember when we used to get Jo like this growin’ up?" Dean asked, hands hovering dangerously close to Cas’ ribcage. 

"Ooh, yeah, she cried the last time we got her at Christmas,” Sam was fiddling with his socks and Cas kicked frantically. Sam adjusted his hold to scratch his nails devilishly over his arch.

He yelped. Sam was evil. Dean was evil too. Evil as he was beautiful, Cas concluded.

"Both of you are such children! Get your fat asses off of me!" Cas gave another valiant kick that almost shook Sam off but did nothing to Dean’s hold on his upper body. The older brother just looked smug. 

"Are you finished?" Dean rose an eyebrow as if to challenge him.

Cas forced himself to breathe, but desperately wanted to shrink under his gaze, hating that he had to look at his stupid pretty face and pretty eyes and painfully beautiful (if totally evil) teasing smile. 

"Let’s see if you’re as bad as Sammy," Dean ruffled Cas’ hair like he was a child and he shook his head in frustration. "How about here?

"Do-ho-hon’t!" Cas’ laughter came out in a colorful range of curses and empty threats as Dean tortuously walked his fingers down from his uppermost ribs to his sides. "Ple-hee-se!" 

"What about here?" Sam started in at his flailing feet in earnest and Cas let out a grunt and a series of breathier giggly protests. 

Dean was in trouble. The boy’s beautiful features only got better mid-laugh, his eyes clenched shut and opened wide as each new weak spot was located and exploited. As his arms strained under his knees, his muscles were hard to ignore; Dean thought the guy had to be a swimmer or a runner and fought back images of him covered in sweat or coming out of the pool like some twisted scene from an 80’s movie. 

Cas’ laughter jumped an octave and Dean found that getting too close to his armpits was the cause. 

"D’aw Sammy, he’s just like you here!" Dean jabbed his thumbs into the defenseless territory and reveled in the honest-to-god squeal that came out. His pinned arms did their best to flail and protect the area but Dean used one hand to hold them still as he continued his assault.

Cas couldn’t tell if Sam had stopped his assault on his lower body or if Dean was just that lethal of a tickler but all he could feel was Dean’s fingers moving over the skin of his underarms, spidering and poking and scratching him into steady hysterics. He twisted his body as best he could, anything to get a bit of relief for that area.

"I think you broke him," Sam laughed somewhere in the distance as Dean moved his fingers to a gently, only slightly unpleasant, wiggling over his stomach. 

"He’s fine. Right, Cas? You’re a fighter."

"You’re a monster and I hate yo-please! Not there, no pleaahahaha!" Cas was interrupted by Dean poking his finger around his belly button. Sam’s hands reached and pinched at his hips making him squeak.

"Just like you, Dean," Sam grinned. Cas tried to file the information away but found the revenge part of his brain was lacking oxygen.

"Psh. You wish, bitch," Dean lifted his hands to let Cas breathe and raised an eyebrow at the panting, sweaty face below him. 

"So, what was Sammy saying?" He walked his fingers right back toward his underarms and Cas started to babble through giggles, shaking his head desperately.

"Don’t, don’t, don’t! Please don’t do that! I’m sorry, Sam was just saying something embarrassing and he was teasing me about it and it wasn’t anything," Cas hid his face in his arm, rocking back and forth as he bit his lip in a way Dean thought should be criminal. "Just no more."

"He’s had enough," Dean found the merciful part of him taking over, giving the younger man access to his arms again as he sat up. Sam scowled giving a well-placed squeeze to Cas’ thigh to make him scream out one more time before he got up.

Cas immediately planted both feet flat on the floor and curled up as much as he could, muttering “evil” through residual giggles. The three sat on the floor to catch their breath.

"You know, Cas," Sam’s face lit up as he noticed the oxygen-deprived look fading from his friends face. "Dean’s more ticklish than both of us combined."

"Really, now?"


	2. Part II: Dean's Turn

**Summary for the Chapter:**

> Dean gets his and Sam is tired of everyone playing coy.

"Look at that it’s… wrist o’clock," Dean glanced at his arm and immediately tried to spring to his feet, but Sam wrapped his own legs around his brother’s, and struggled to pull him back to the floor. Cas scrambled to sit on his chest to keep him down. 

"Off," Dean trained his face into a more serious one, looking pointedly at Cas, who raised an eyebrow as he jabbed his fingers into Dean’s side, smirking as he flinched.

Dean reached up to pinch back, but Cas quickly caught one hand and then the other and manhandled them under his knees with something like a small victorious smile (that was totally not cute at all, no sir) taking over his face.

"So, Dean," Sam grinned, tweaking at his knee and making him curse under his breath. "What’s first? Hips, pits, knees or feet?" 

"Bite me, Sammy," he gritted his teeth. Cas saw that under the bravado Dean was struggling hard to break their hold, panic flashing under his glare.

"Let’s do an experiment to see which spots make him scream like a little girl," Sam teased knowing it would fluster Dean even more. "Sound good, Cas?" 

"I think I can catch on," Cas saw Dean’s eyes turn from defiant to pleading in a second and he almost regretted what he was about to do. Almost. "For science."

"So, let’s see…" 

Sam grabbed at Dean’s two big toes and pulled them back with one hand and Dean took a sharp intake of breath, clenching his eyes shut. Come on. 

Sam’s finger traced at the lines along his feet and Dean’s entire body tried to squirm, air escaping his mouth in little puffs as he tried to hold his breath and laughter in. His head slammed back against the carpet with a grunt.

"Sah-ahmmy," his voice warned as he seized up again. Cas pushed his shoulders back down and clicked his tongue. 

"Your feet aren’t even that bad, Dean," Sam teased, scratching his fingers softly along his foot, focusing right under his toes. "Except this spot, it’s real bad."

Dean let out an undignified yelp. Certainly not a sound that should be coming out of a 19 year old. 

"Fuh-uhck you-hoo!" Dean twitched and cursed himself for giving them that reaction. He knew better than anyone that his brother would feed off of that. "Stop!" 

"Why?" Sam gave him wide, dumb eyes and Dean pounded his head back against the floor. "What’s wrong, Dean? Use your words."

The mocking tone only made things worse, increasing his agitation. That, and the little problem of his brother’s gorgeous friend sitting on his chest and looking down at him with his stupidly pretty eyes had him feeling more on edge and somehow even more sensitive. 

"I- fuck!" Dean let out a little gasp when Cas reached behind him to tweak at his knee, wiggling his fingers along the sensitive undersides. "C’mon. Please. It feels weird, it —" 

"Weird? I’m sorry, Dean, I don’t follow," Sam was going to get his scrawny beanpole ass kicked into next week, Dean decided between grunts as Cas’ fingers joined Sam’s in the assault on his lower body. 

He felt his face getting more pink as his giggles started to spill out in desperate gasps.

"Tell me why I should stop, Dean — Cas, get his hips," he directed. "And maybe, just maybe, I will." 

"No! Cahahahas!" Dean seized up in as much of a jack-knife as he could manage. His resolve crumbled as Cas reached behind, his irritatingly long fingers squeezing and scratching at his hips, thumbs needling into his bones and spidering along the softest parts of his flanks.

"C’mon, it tihihihick —" he sputtered when Cas went back and forth between drilling his thumbs and scratching his fingers at a maddening pace.

"You gotta say it, Dean," Sam sing-songed, "Or you could just tell me and Cas why you’ve been hovering around us so much lately and apologize for teasing him constantly.” 

"Huh?" that caught Cas’ attention, his fingers slowing to make small rhythmic circles over the bones. He thought he was just being creepy, the way he ogled at Dean all summer. It didn’t even occur to him that the older Winchester was trying to get those reactions.

"Dohohon’t," Dean heaved, as Sam went back to fiddling with his toes. "Quihihihit ihihihit!" 

"What was Sam saying," Cas paused, making eye contact with Dean and leaning forward, watching the pink flush under his freckles. "Why all the ‘hovering and teasing,’ Dean?"

"S’nothing. It’s stupid," Dean mumbled, tugging lightly at his wrists under Cas’ legs, not sure why he couldn’t break eye contact. "I wasn’t." 

"Bullshit," Sam reached forward and gave his brother’s hips a squeeze. "Tell him how you liked getting him all flustered."

"You were doing that on purpose?" Cas’ eyes narrowed, not sure where this was going. "Why?" 

"It’s because he’s an emotionally stunted jerk," Sam sighed. "And he likes you.”

"Oh?" Cas couldn’t fight his grin as Dean’s blush rose even more.

"Ugh, shut it, Sam," Dean rolled his eyes and tried to look everywhere Cas wasn’t.

"Sam, can you excuse us for a minute?" Cas kept his eyes trained on Dean’s, as his friend tossed them both a wink before nearly skipping out of the room. 

"You like me, huh?”

Dean hated how drop dead sexy Cas’ teasing tone was, deep and slow and perfect with a confident edge. He liked it even more than his flustered one.

"Don’t make me regret it," he groaned. 

But he couldn’t hide the shock on his face when Cas leaned down, shifting his legs off his wrists, and pressed a soft kiss to his lips. 

"I don’t plan on it.


End file.
